The present invention relates to GaAs integrated circuit technology, and in particular, to a novel means of controlling oxidation growth rate on anodically oxidized GaAs samples.
In U.S. Pat. No. 3,345,274 a method of making oxide film patterns on silicone semiconductor samples is disclosed where visible, near infra-red or infra-red light is projected onto the semiconductor substrate and functions to provide minority carriers so that anodic oxide formations can occur. Furthermore, application of such light for rear surface illumination in addition to application of a retarding blue light (about 4500.degree. A) for front surface illumination is disclosed in that patent for production of oxide patterns on a silicone semiconductor sample under DC-bias by means of an electrochemical process.
However, such patent does not teach a controlled process for electrochemical oxide growth where both accelerating and retarding illumination beams are employed on the same working surface of a GaAs semiconductor sample to produce a defined oxide growth pattern. As well, no technique for use of a masked accelerating beam is disclosed or taught in such prior art.